Tim wrote:
My small boat has steel, my large boat has aluminum and my old cruiser
had brass. The steel looks pretty and is less prone to damage (it can
tear up the lower end instead) and the aluminum is more prone to wear and
is waddable if you hit something, obviously the steel is a lot more
expensive than the pot metal ones, but what really is the advantage of
the steel really if any? Brass seemed to be in the middle somewhere. Can
you still get brass props for runabouts anymore?

Steel are more efficient. You can have a thinner blade, better profile.
My jet drive has stainless impellers. Pump gravel better. Have to take a
grinder to them once in a while if running shallow gravel rivers. Sand
just polishes the blades.